presidential debate veteran senator john kerry is participating in the mock debates, pretending to be a different patrician wealthy massachusetts pol, mitt romney. yesterday, in las vegas, the president tried to lower expectations. >> i know folks in the media are speculating already on who's going to have the best zingers. >> you are! >> governor romney, he's a good debater. i'm just okay. >> reporter: a new "washington post"/abc news poll shows the president enjoys advantages going into this debate. 66% say his policies have favored the middle class, while 57% think romney's, instead, would favor the wealthy. but the campaign sees some liabilities, as well. the president can get peevish when challenged. >> you're likable enough, hillary. >> reporter: his debate prep team is also studying presidential debates of the last 20 or so years, focusing on unforced stylistic errors, such as al gore's exasperated sighs. the president is also quite verbose. when i asked him a two-part question in august, his answer was -- >> on afghanistan. >> reporter: longer than 5 1/2 minutes. he's working